Array.TrueForAll() Method in C#

The Array.TrueForAll() method in C# is used to determine whether every element in the array matches the conditions defined by the specified predicate.

Syntax

Following is the syntax −

public static bool TrueForAll<T> (T[] array, Predicate<T> match);

Example

Let us now see an example to implement the Array.TrueForAll() method −

using System;
public class Demo{
   public static void Main(){
      Console.WriteLine("Array elements...");
      string[] arr = { "bike", "bus"};
      for (int i = 0; i < arr.Length; i++){
         Console.Write("{0} ", arr[i]);
      }
      Console.WriteLine();
      int lastIndex = Array.LastIndexOf(arr, "bus");
      Console.WriteLine("Last Ocurrence of element bus is at index = "+lastIndex);
      bool res = Array.TrueForAll(arr, ele => ele.StartsWith("b",
      StringComparison.Ordinal));
      if (res)
         Console.Write("Every element in the array matches the conditions defined by the specified predicate.");
      else
         Console.Write("Eevery element in the array do not matche the conditions defined by the specified predicate");
   }
}

Output

This will produce the following output −

Array elements...
bike bus
Last Ocurrence of element bus is at index = 1
Every element in the array matches the conditions defined by the specified predicate